我尝试运行SoftKeyboard示例以确保我的所有安装都正常工作，包括模拟器。似乎构建很好，除了模拟器似乎停留在Android初始化并且没有键盘出现。我随机挑选了Nexus作为我的设备。消息是
[2014-04-20 18:01:57 - SoftKeyboard] Performing sync
[2014-04-20 18:01:58 - SoftKeyboard] Automatic Target Mode: launching new emulator with compatible AVD 'AVD_Nexus'
[2014-04-20 18:01:58 - SoftKeyboard] Launching a new emulator with Virtual Device 'AVD_Nexus'
[2014-04-20 18:02:50 - Emulator] emulator: emulator window was out of view and was recentered
[2014-04-20 18:02:50 - Emulator]
[2014-04-20 18:02:50 - SoftKeyboard] New emulator found: emulator-5554
[2014-04-20 18:02:50 - SoftKeyboard] Waiting for HOME ('android.process.acore') to be launched...
[2014-04-20 18:17:37 - SoftKeyboard] WARNING: Application does not specify an API level requirement!
[2014-04-20 18:17:37 - SoftKeyboard] Device API version is 19 (Android 4.4.2)
[2014-04-20 18:17:37 - SoftKeyboard] HOME is up on device 'emulator-5554'
[2014-04-20 18:17:37 - SoftKeyboard] Uploading SoftKeyboard.apk onto device 'emulator-5554'
[2014-04-20 18:17:37 - SoftKeyboard] Installing SoftKeyboard.apk...
[2014-04-20 18:20:16 - SoftKeyboard] Failed to install SoftKeyboard.apk on device 'emulator-5554!
这条消息是什么意思？应该使用什么设备？